Riffle



April 17, 1945. D. s'. UPHAM v2,373,931

ZY Q A al v v E #t Patented Apr. 17, 194,5y

UNITED STATES PATENT OFFICE RIFFLE David S. Upham, Fort Jones, Calif. Application December 14, 1942, Serial No. 468,961

' s claims. (c1. 209-458) for illustration, the riiiie I comprises two sheets I2 and I4 of expanded metal placed face tol face and welded into a unitary structure, as at I6. One corner portion only of the riille is shown in the drawing, but the construction is the same throughout the entire area of the riflie. A corresponding fragment I8 of a sluice box is lalso shown, the rillle I0 lying on the box bottom 2l).A

In Figure 1, the uncut portions 22 of the sheet I2 are spaced equal distances one from the other along the lines 24, this being true also of the uncut portions26 of the sheet I4. Both uncut portions 22 and 26 are respectively spaced equal distances one from the other along the lines 28,

so fully illustrate my invention, that others may,

by applying current knowledge, readily adapt the same for use under various conditions of service.

I claim:

1. A riflie comprising similar sheets of metal each cut and expanded to provide ribs and uncut portions interconnecting the ribs, said sheets disposed face to face with the ribs of one sheet crossing the ribs of the other sheets, and contacting parts of said sheets secured together one to the other so that said sheets form a substantially integral unit, said uncut portions being rectangular in cross section with their major axes arranged at acute angles to planes of their respective sheets.

2. A riffle comprising similar sheets of metal each cut and expanded to provide ribs and uncut portions interconnecting the ribs, said sheets and the sheets l2 and I4 are so arranged 'as to K Y impinges againstthe acute angle faces of the uncut portions 22 and 26 and the ribs 32 and 34' interconnecting the portions 22 and 26, respectively.

A rile in accordance with my invention provides a network of uncut portions 22 and 26, ribs 32 and 34 and a system of interstices 36 which operate to separate, catch and retain the valuable metal in an eiiicient manner. The rifile is exceptionally durable and easily and cheaply constructed in all necessary sizes and lengths.

Without'further elaboration, the foregoing will lying face to face in contacting relationship with the ribs -of one sheet crossing and secured to the ribs of the other sheets, such securing means l for the sheets one to the other forming a sub-r stantially unitary, integral, and reversible unitl of the sheets, and a sluice means carrying the rile, said uncut portions having upstream faces lying at acute angles to the planes of their respective sheets.

uncutA portions being of elongated rectangular cross section and inclined to the plane of the screens and the iloor surface,r the contacting portions ofsaid screens being rigidly secured one upon the other with the uncut portions of one screen disposed centrally of the expanded ribs of the other, the uncut portions oi the lowermost screen resting on the floor surface of the sluice box and the uncut portions of the upper screen assuming a position raised above said surface a distance corresponding to approximately onehalf the longitudinal cross sectional dimension of said portions.

DAVID S. UPHAM. 

